Hemorrhoids and similar lesions (internal hemorrhoids, external hemorrhoids, perianal skin tags) are a frequent source or morbidity in the general population and in specific high-risk groups, such as those with spinal cord injuries. Surgical operation was long the mainstay of hemorrhoid treatment, but it has been largely replaced by a number of non-operative techniques, one of which is elastic ring ligation.
In this type of procedure, a tight elastic ring is placed around the base of the hemorrhoid, causing loss of blood supply and tissue death. The term "elastic" is used to indicate the propensity of an object for recovering its original size and shape after deformation by forces such as stretching. Elastic ring ligation may be accompanied by injection of medication for chemical destruction of the hemorrhoid. Elastic ring ligation is usually done without anesthesia or hospital admission, reducing costs and making it a procedure of choice both in industrialized and developing countries.
As generally practiced, elastic ring ligation requires three hand-held instruments: an endoscope (anoscope or anal speculum), a forceps, and a ligator. The endoscope has within it a removable, handled mandrel called an obturator, which facilitates the insertion of the endoscope into the orifice. Typically, the surgeon first introduces the endoscope (with the obturator in place) into the patient's anus to visualize the target lesion. The obturator is then withdrawn, allowing the surgeon to visualize the patient's hemorrhoids. As an assistant holds the endoscope in place, the surgeon grasps the hemorrhoid with the forceps and draws it through the barrel of the ligator, onto which a contractible elastic ring has previously been stretched. The elastic ring is displaced off the barrel of the ligator onto the base of the lesion. A problem with the procedure as typically practiced is that it requires at least three hands to perform, necessitating the presence of an assistant
Prior art devices address this problem in two major ways: either two of the three instruments are combined or suction is used to substitute for forceps. In the former category, prior art includes a combination of forceps and ligator (Blaisdell's device, depicted in Diseases of the Colon and Rectum 6:110, 1963) and combinations of endoscope and ligator (U.S. Pat. No. 3,760,810 to Van Hoorn, Sept. 25, 1973, and Thomson's device, depicted in Lancet 2:1006, 1980). In the latter category, suction ligators include a described embodiment of Van Hoorn's device (cited above), the preferred embodiment in U.S. Pat. No. 4,257,419 to Goltner et al. (Mar. 24, 1981), and the Pyser device, depicted in British Journal of Surgery 71:212, 1984.
Suction ligators are only useful where controllable suction is available, making their use impractical in many offices, clinics, and hospitals both in industrialized and developing countries. In addition, the size of the lesion to be ligated is strictly limited by the depth of the suction vessel, a serious limitation for the aforementioned Goltner and Pyser devices.
Blaisdell's aforementioned combination of forceps and ligator has the disadvantage that the forceps and ligator are not self-retaining within the endoscope, forcing the surgeon to manage both forceps and ligator elements simultaneously with one hand, which is not practical. An assistant is still required to hold the endoscope while the surgeon operates the forceps and ligator with two hands.
Van Hoorn's and Thomson's devices, each of which combines endoscope and ligator in a single instrument and leaves the forceps to be manipulated by the surgeon's free hand, are usable by a single operator, but they stop short of uniting all three instruments in an efficient combination. In addition, they have the disadvantage of requiring the use of two hands at all times during the procedure.
There are many variations in design of the three instruments (ligator, forceps, and endoscope) used in elastic ring ligation of hemorrhoids. A large number of ligator design variations exists. Among ligators, variations in the grip for the actuation mechanism include pistol-grip (Barron type, depicted in American Journal of Surgery 105:563, 1963), speculum-grip (McGivney type, depicted in Texas Medicine 63(5):57, 1967), finger-ring grip (Rudd Clinic type, depicted in Canadian Medical Association Journal 108:57, 1973), scissors-grip (Keighley type, depicted in American Journal of Proctology, Gastroenterology, & Colon & Rectal Surgery 30(3):35, 1979), etc.
Variations in the mechanism for pushing the contractible elastic ring off the ligator's barrel include the use of a dual barrel (U.S. Pat. No. 3,382,873 to Banich et al., May 14, 1968, or Barron or McGivney type, cited above), the use of a pullstring (Lamm type, depicted in Diseases of the Colon and Rectum 16:547, 1973), the use of a pushrod (Rudd Clinic type, cited above), etc. For elastic ring ligation accompanied by injection of medication for chemical destruction of the hemorrhoid, a needle and injection port can be affixed to the ligator (Orlay type, depicted in Medical JournaI of Australia 2:420, 1979).
Numerous varieties of forceps can be used to grasp hemorrhoids for elastic ring ligation; the most practical are toothed, including Allis type and hemorrhoid grasping forceps (depicted in American JournaI of Surgery 105:564, 1963). Endoscopes used for hemorrhoid treatment are typically either solid-sided or slotted. For the purposes of this invention, all the above variations in ligator, forceps, and endoscope are considered equivalent, as this invention relates to a new device which combines the three instruments.
Likewise, several variations of elastic ring design exist. U.S. Pat. No. 4,794,927 to Yoon, Jan. 3, 1989, describes a family of elastic rings incorporating different types of interconnecting elements. These have, to varying degrees, the advantage of adhering more securely to the hemorrhoid (or other ligated structure) than the smooth elastic ring used conventionally. For the purposes of this invention, these variations in the design of elastic ring are considered equivalent, as this invention relates to a new device which combines ligator, forceps, and endoscope.